P00A3 medium Severity

P00A3: Charge Air Cooler Temperature Sensor Circuit High Bank 2

Illuminated check engine light, possible reduced engine performance, fuel economy loss, and potential limp mode in some turbocharged engines

Overview

P00A3 OBD-II diagnostic trouble code indicates a high condition in the charge air cooler (intercooler) temperature sensor circuit on engine bank 2, often due to sensor or wiring issues

Common Symptoms

  • Check Engine Light illuminated
  • Poor engine performance or reduced power
  • Decreased fuel economy
  • Engine may enter limp mode or restrict performance

Most Common Causes

Faulty charge air cooler temperature sensor high

Sensor failure is frequently identified as the primary cause when proper 5V reference and ground signals are present

Wiring harness or connector issues (open, short, or corrosion) high

Open circuits or shorts to ground/battery in the sensor wiring often trigger the high circuit condition

Poor 5V reference supply from PCM or bad ground medium

If the PCM cannot provide correct reference voltage, the sensor reading may erroneously appear high

Failed or restricted charge air cooler or intercooler issues low

Less common; temperature anomaly can be caused by airflow issues affecting sensor readings

Faulty PCM low

Rare cause but possible if other causes are ruled out

Diagnostic Steps

  1. Verify code and freeze frame data with a professional OBD-II scan tool
    Expected: P00A3 present and related freeze frame data available
    Interpretation: Confirms current or stored code before beginning physical diagnostics
  2. Inspect wiring and connector to the bank 2 charge air cooler temperature sensor
    Expected: No broken, pinched, corroded wiring or loose connectors
    Interpretation: Damaged wiring or poor connection can cause high circuit codes
  3. Check for proper 5V reference at sensor with ignition on using a voltmeter
    Expected: Approximately 5 volts at reference wire
    Interpretation: No reference voltage suggests PCM or harness issue
  4. Test sensor resistance relative to known temperature/resistance specifications with engine warm
    Expected: Resistance decreases smoothly with increased air temperature
    Interpretation: Non‑changing or out‑of‑spec resistance indicates faulty sensor
  5. Check sensor ground continuity to PCM and chassis ground
    Expected: Low resistance to ground
    Interpretation: Open or high resistance suggests grounding issue

Repair Solutions

Replace faulty charge air cooler temperature sensor medium
Estimated Cost: $100 - $300

Sensor replacement cost varies by vehicle; includes parts and labor

Repair or replace damaged wiring/connectors medium
Estimated Cost: $50 - $200

Cost depends on extent of wiring damage and access

Repair PCM reference voltage or ground circuits hard
Estimated Cost: $150 - $600

May require professional diagnostics and PCM work

Replace or clean charge air cooler assembly if airflow issues are confirmed hard
Estimated Cost: $300 - $1200

Intercooler service typically necessary only if physically damaged or clogged

Common Misdiagnoses

Avoid these common diagnostic mistakes:

  • Misinterpreting high circuit code as overtemperature condition without electrical diagnosis

Frequently Asked Questions

What does a P00A3 diagnostic trouble code signify?

Technically, the P00A3 code represents Charge Air Cooler Temperature Sensor Circuit High Bank 2. It usually points to a fault within the Sensors.

How serious is the P00A3 code?

The P00A3 code is considered medium severity. Illuminated check engine light, possible reduced engine performance, fuel economy loss, and potential limp mode in some turbocharged engines

Symptoms associated with DTC P00A3

You may experience the following: Check Engine Light illuminated, Poor engine performance or reduced power, Decreased fuel economy.

Common triggers for the P00A3 error

The most common causes are: Faulty charge air cooler temperature sensor, Wiring harness or connector issues (open, short, or corrosion), Poor 5V reference supply from PCM or bad ground.

How much does it cost to fix P00A3?

Expect to pay around $200 if the issue is a Repair or replace damaged wiring/connectors, but up to $1200 if the Replace or clean charge air cooler assembly if airflow issues are confirmed needs replacement.

What cars are affected by the P00A3 code?

Yes, P00A3 is a generic code that applies to all OBD-II compliant vehicles, including Ford, Toyota, Honda, Chevrolet, Nissan, Dodge, BMW, and more.

User Comments (0)

Share your experience or ask a question about this code.

Be the first to share your experience with P00A3!